Molecular Structure and Functional Propeerties of a High Molecular Weight-Multiprotease Complex
| Project/Area Number |
62570114
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
General medical chemistry
|
|---|
| Research Institution | The University of Tokushima |
|---|
Principal Investigator |
TANAKA Keiji Institute for Enzyme Research, University of Tokushima, 酵素科学研究センター, 助手 (10108871)
|
|---|
| Project Period (FY) |
1987 – 1988
|
| Project Status |
Completed (Fiscal Year 1988)
|
| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1988: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1987: ¥1,600,000 (Direct Cost: ¥1,600,000)
|
|---|
| Keywords | Intracellular Protease / Multifunctional Enzyme / Multisubunit Complex / Molecular Structure / 分子構造 / 活性調節 / プロテアソーム / 細胞内分布 / 遺伝子構造 / 造腫瘍性変動 / 高分子量プロテアーゼ / プロテアーゼ複合体 / 20S粒子 / 多機能酵素複合体 |
|---|
| Research Abstract |
Proteasomes (large multiprotease complexes) purified from various eukaryotic sources, namely human, rat and chicken livers, Xenopus laevis ovary and yeast showed similar activities, such as latent proteinase and multiple peptidase activites. All the proteasomes showed very similar physicochemical properties, such as a sedimentation coefficient of 20S and molecular weight of 800kDa. Electron microscopy showed that they all also had similar well-defined symmetrical morphology and appeared to be ring-shaped particles with a small hole. Thus, proteasomes from various sources were strikingly similar in gross structure, but they were distiguishable by Ouchterlony double diffusion analysis and immuno-blot analysis using antibodies raised in rabbits against each enzyme. On two dimensional electrophoresis, these proteasomes separated into 15-20 characteristic components with molecular weights of 22 KDa to 33 KDa and isoelectric points of 4 to 9 and their subunit multiplicity showed species-specific differences. The nucleotide sequence of the largest component of the rat liver proteasomes was determined from a recombinant cDNA clone isolated by screening a rat liver cDNA library. This subunit is the unmodified product of a single gene, suggesting that the multiple subunits of proteasomes are likely each to be coded by a different gene. Thus, proteasomes are thought to be unusual enzyme complexes consisting of non-identical multiple subunits. This work shows that proteasomes with a similar molecular organization, but differences in subunit multiplicity and immunological reactivity are widely distributed in various eukaryotic organisms ranging from man to yeast. This ubiquitous distribution implies the general importance of proteolysis catalyzed by these proteasomes.
|
Report
(3 results)
Research Products
(41 results)
